Edward S. Van Vleet

Acyclic archaebacterial ether lipids in swamp sediments

Abstract Acyclic phytanyl diether glycerol and biphytanyl ether lipids have been quantified in two modern swamp sediment cores in concentrations ranging up to 360 μg/ml porewater. Methanogenic bacteria are the only known source organisms which can inhabit the swamp sediments. Variations in relative abundance between these lipids may reflect taxonomic changes in methanogen populations or the stage of growth. Maxima in methanogen lipid concentrations coincide with local maxima of 13 C of organic matter, possibly the result of a pool effect on CO 2 or acetate. Methane production estimates calculated from lipid concentrations in swamp sediments range from 0.1 to 1.3 mmol cm −2 yr −1 , values which are consistent with published methane fluxes.

Persistence of petroleum hydrocarbon contamination in sediments of the canals in Venice, Italy: 1995 and 1998.

Total hydrocarbon and selected polycyclic aromatic hydrocarbon (PAH) levels were examined in sediments collected from known problematic areas in the canals of Venice, Italy, in 1995 and 1998. Hydrocarbon concentrations were greatest in the interior canals, moderate in the partially enclosed locations and lowest in the open-water sites. Total hydrocarbon and PAH concentrations declined from 1995 to 1998. Ancillary data suggest that this decline may have been in response to the elimination of many industrial activities in the lagoon and to initiating an aggressive canal dredging program. The distributions of individual components were generally similar both years regardless of the total PAH concentration or the location of sample collected. PAH alkyl homolog distributions suggest that atmospheric deposition of petrochemical combustion products is the main source of PAHs to Venices sediments. In some cases however, the presence of low levels of the two-ring naphthalene homologous series indicate additional low-level inputs of fresh oil.

Comparison of lipids in selected tissues of the Florida manatee (Order Sirenia) and bottlenose dolphin (Order Cetacea; Suborder Odontoceti).

The position, porosity and oil-filled nature of the zygomatic process of the squamosal bone (ZPSB) of the Florida manatee, Trichechus manatus latirostris, suggest that it may have a similar sound conduction function to that of the intramandibular fat body (IMFB) of the bottlenose dolphin, Tursiops truncatus, and other odontocetes. To examine this possibility we determined the lipid composition of the ZPSB and adipose tissue from the dorsal part of the head region of the Florida manatee, and compared it to that of the dolphin IMFB and melon (another fatty area implicated in sound conduction in odontocetes). Lipids from manatee ZPSB and from adipose tissue were composed almost entirely of triacylglycerols. The most abundant fatty acids of the ZPSB were 18:1, 16:0, 14:0 and 16:1. The major fatty acids of the adipose tissue in the head were the four mentioned above, along with 12:0 and 18:0. Manatee samples did not contain isovaleric acid (iso-5:0), which was found in the bottlenose dolphin IMFB and melon, and has been related to sound conduction in dolphins and some other odontocetes. Thus, if manatee tissues are capable of sound conduction, and this process does occur through the ZPSB, a somewhat different suite of lipid components must support this function.

Organochlorine residues in the Florida manatee, Trichechus manatus latirostris

Forty-five tissue samples, consisting of 15 liver samples, 19 kidney samples and 11 blubber samples from the Florida manatee, Trichechus manatus latirostris, were analysed using gas chromatography and combined gas chromatography-mass spectrometry for a variety of chlorinated hydrocarbons. Pesticides (o,p-DDT, o,p-DDD, hexachlorobenzene and lindane) were detected in all three tissues, but they were found most frequently in the liver and kidney. However, due to the low frequency of observed pesticides, their concentrations could not be related to age, sex, length or the geographical location where the manatee carcasses were recovered. Compared to most manatees in the study, one female perinatal manatee born in captivity had elevated concentrations of lindane in the liver and o,p-DDD in the kidney, suggesting that the pesticides found in this animal were transferred from the mother prior to birth.

SUBLETHAL INJURY TO RED MANGROVES TWO YEARS AFTER OILING1

ABSTRACT More than 300,000 gallons of refined petroleum products were discharged near the entrance to Tampa Bay, Florida on August 10, 1993. Floating slicks and sunken oil patty (no. 6 fuel oil) subsequently entered Boca Ciega Bay through Johns Pass and washed or stranded on four mangrove keys inside the pass. Between one and two years after the spill, surviving red mangroves showed graded negative responses to oil in 4 of 4 measures of shoot growth and production. Sublethal, long-term effects of oil spills may be more common than reported, but detection requires detailed data on species-specific growth and production patterns with respect to oiling.